The Beta C-Mag is a 100-round capacity

drum magazine A drum magazine is a type of high-capacity magazine for firearms. Cylindrical in shape (similar to a drum), drum magazines store rounds in a spiral around the center of the magazine, facing the direction of the barrel. Drum magazines are contrast ...

manufactured by the Beta Company. It was designed by Jim Sullivan and first patented in 1987 and has been adapted for use in numerous firearms firing the

5.56×45mm NATO The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, but often pronounced "five-five-six") is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, and ...

7.62×51mm NATO The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rimless, bottlenecked rifle cartridge. It is a standard for small arms among NATO countries. First developed in the 1950s, the cartridge had first been introduced in U.S. service fo ...

, and

9×19mm Parabellum The 9×19mm Parabellum (also known as 9mm Parabellum or 9mm Luger or simply 9mm) is a rimless, tapered firearms cartridge. Originally designed by Austrian firearm designer Georg Luger in 1901, it is widely considered the most popular handgun a ...

cartridges. ''C-Mag'' is short for ''century magazine'', referring to its hundred-round capacity. It has two drum units, each of which hold half of the cartridges inserted into the magazine. The latest version of the magazine is available with a transparent backing to allow the user to see the number of rounds remaining in the magazine. A C-Mag loaded with

ammunition typically weighs about ; a C-Mag loaded with

ammunition weighs . A version adapted for the M16 rifle is used by the

U.S. military The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...

. The magazine design, including drawings, is covered in detail in .

Design

The C-MAG is a compact twin-drum magazine design that accepts up to 100 rounds of ammunition. It consists of two main components: the twin-drum storage housing and an interchangeable feed clip assembly. The storage housing is standard and fits any like-caliber weapon. The feed clip assembly serves as an adapter for the specific weapon. Before loading and after firing, the feed clip is filled with spacer rounds that are an integral part of the magazine. The upper half of the top spacer round is tapered to allow the weapon bolt to close after the last round is fired. The length of the string-set depends on the customized feed clip for the individual weapon. During loading, cartridges are inserted on top of the spacer rounds, through the feed clip and into the drums. The cartridge column splits at the juncture of the feed clip and the housing to distribute the ammunition evenly into the drums in two concentric rows. During firing, spring-driven rotors advance the cartridges in both drums until they meet at a cam blade that merges the cartridges into a single column that feeds up through the feed clip and into the weapon.

Firearms compatible with C-MAG magazines

* Colt 9mm SMG * Heckler & Koch MP5 * Uzi * Glock, plus these firearms using a Glock magazine: ** KRISS Vector Gen II ** Kel-Tec SUB-2000 * CZ Scorpion Evo 3 G36 CMag

( STANAG magazine with Mini-14 compatibility) * FN Minimi * M249 light machine gun * Ultimax 100 * AR-15 * Beretta ARX-160 * FN SCAR * Heckler & Koch G36 * Heckler & Koch HK33 * Heckler & Koch HK416 * Heckler & Koch HK 93 * Heckler & Koch XM8 * M4 carbine * M16 rifle * PVAR rifle *

Ruger Mini-14 The Mini-14 is a lightweight semi-automatic rifle manufactured by Sturm, Ruger & Co. Introduced in 1973, it is based on the M14 rifle and is essentially a scaled-down version chambered in 5.56×45mm NATO. It is made in a number of variants, inc ...

* SA80 * SIG SG550 / 551 / 552 / 553 / 556 *

Steyr AUG The Steyr AUG () is an Austrian bullpup assault rifle chambered for the 5.56×45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG. It was adopted by the Austrian Arm ...

* CZ 805 BREN

* AR-10A, and various firearms using SR-25 pattern magazines. *

FN FAL The FAL (a French acronym for (English: "Light Automatic Rifle")), is a battle rifle designed in Belgium by Dieudonné Saive and manufactured by FN Herstal (simply known as FN). During the Cold War the FAL was adopted by many countries of th ...

(no longer available) * FN SCAR (modified FAL-pattern) *

Heckler & Koch HK91 The Heckler & Koch HK41 is a semi-automatic version of the Heckler & Koch G3 battle rifle; it was produced by Heckler & Koch for the civilian market in the 1960s.

and Heckler & Koch G3 * M14 rifle * AR-10B (modified M14-pattern)

Performance evaluations

Reliability

A test in 2003 by U.S. Army soldiers in Afghanistan found the C-Mag unreliable in simulated

combat Combat ( French for ''fight'') is a purposeful violent conflict meant to physically harm or kill the opposition. Combat may be armed (using weapons) or unarmed ( not using weapons). Combat is sometimes resorted to as a method of self-defense, or ...

conditions and reported frequent failures to feed among the issues; likewise,

British Armed Forces The British Armed Forces, also known as His Majesty's Armed Forces, are the military forces responsible for the defence of the United Kingdom, its Overseas Territories and the Crown Dependencies. They also promote the UK's wider interests, s ...

trials found that the C-Mag did not give reliable performance when loaded with British-issue ammunition. The Beta C-Mag is not in widespread use by U.S. military forces, and has not been type-classified. In November 2008, the U.S. Army Experimental Task Force (AETF) at Fort Bliss, Texas, evaluated six Beta C-Mag magazines. Four magazines—two with black covers and two with clear covers—were used with M4 carbines in three firing scenarios: controlled pair, controlled burst, and rapid fire. According to the memorandum summarizing the evaluation, the four magazines "performed flawlessly in all three scenarios without jams or stoppages." Additionally, two magazines with black covers were evaluated with M249 light machine guns in controlled burst and rapid-fire scenarios. These also performed without "issues," according to the memo, which also notes that soldiers "had only positive comments" about the C-Mag magazines during the After Action Review (AAR). Test-fired with a

Heckler & Koch HK91 The Heckler & Koch HK41 is a semi-automatic version of the Heckler & Koch G3 battle rifle; it was produced by Heckler & Koch for the civilian market in the 1960s.

, Heckler & Koch G3 and two other Heckler & Koch-based weapons, the 7.62mm C-Mag was found to operate without problems in either loading or firing at rates up to 1,000 rounds per minute.

References

External links